При выполнении п.6-7 задания 3, происходит ошибка...

```
/usr/src/app # alembic upgrade head
INFO  [alembic.runtime.migration] Context impl PostgresqlImpl.
INFO  [alembic.runtime.migration] Will assume transactional DDL.
/usr/local/lib/python3.11/site-packages/alembic/script/revision.py:242: UserWarning: Revision a4735d35d75 referenced from a4735d35d75 -> b8d7c7eca9a6 (head), Add User.patronomic is not present
  util.warn(
Traceback (most recent call last):
  File "/usr/local/bin/alembic", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/config.py", line 641, in main
    CommandLine(prog=prog).main(argv=argv)
  File "/usr/local/lib/python3.11/site-packages/alembic/config.py", line 631, in main
    self.run_cmd(cfg, options)
  File "/usr/local/lib/python3.11/site-packages/alembic/config.py", line 608, in run_cmd
    fn(
  File "/usr/local/lib/python3.11/site-packages/alembic/command.py", line 403, in upgrade
    script.run_env()
  File "/usr/local/lib/python3.11/site-packages/alembic/script/base.py", line 583, in run_env
    util.load_python_file(self.dir, "env.py")
  File "/usr/local/lib/python3.11/site-packages/alembic/util/pyfiles.py", line 95, in load_python_file
    module = load_module_py(module_id, path)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/util/pyfiles.py", line 113, in load_module_py
    spec.loader.exec_module(module)  # type: ignore
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap_external>", line 940, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/usr/src/app/alembic/env.py", line 76, in <module>
    run_migrations_online()
  File "/usr/src/app/alembic/env.py", line 70, in run_migrations_online
    context.run_migrations()
  File "<string>", line 8, in run_migrations
  File "/usr/local/lib/python3.11/site-packages/alembic/runtime/environment.py", line 948, in run_migrations
    self.get_context().run_migrations(**kw)
  File "/usr/local/lib/python3.11/site-packages/alembic/runtime/migration.py", line 615, in run_migrations
    for step in self._migrations_fn(heads, self):
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/command.py", line 392, in upgrade
    return script._upgrade_revs(revision, rev)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/base.py", line 459, in _upgrade_revs
    for script in reversed(list(revs))
                           ^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 813, in iterate_revisions
    revisions, heads = fn(
                       ^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 1438, in _collect_upgrade_revisions
    for rev in self._parse_upgrade_target(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 1229, in _parse_upgrade_target
    return self.get_revisions(target)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 545, in get_revisions
    resolved_id, branch_label = self._resolve_revision_number(id_)
                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 767, in _resolve_revision_number
    self._revision_map
  File "/usr/local/lib/python3.11/site-packages/sqlalchemy/util/langhelpers.py", line 1140, in __get__
    obj.__dict__[self.__name__] = result = self.fget(obj)
                                           ^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 246, in _revision_map
    down_revision = map_[downrev]
                    ~~~~^^^^^^^^^
KeyError: 'a4735d35d75'
/usr/src/app # alembic merge heads -m "Merge migrations"
/usr/local/lib/python3.11/site-packages/alembic/script/revision.py:242: UserWarning: Revision a4735d35d75 referenced from a4735d35d75 -> b8d7c7eca9a6 (head), Add User.patronomic is not present
  util.warn(
Traceback (most recent call last):
  File "/usr/local/bin/alembic", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/config.py", line 641, in main
    CommandLine(prog=prog).main(argv=argv)
  File "/usr/local/lib/python3.11/site-packages/alembic/config.py", line 631, in main
    self.run_cmd(cfg, options)
  File "/usr/local/lib/python3.11/site-packages/alembic/config.py", line 608, in run_cmd
    fn(
  File "/usr/local/lib/python3.11/site-packages/alembic/command.py", line 353, in merge
    return script.generate_revision(
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/base.py", line 682, in generate_revision
    self.revision_map.get_revisions(head),
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 543, in get_revisions
    return sum([self.get_revisions(id_elem) for id_elem in id_], ())
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 543, in <listcomp>
    return sum([self.get_revisions(id_elem) for id_elem in id_], ())
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 545, in get_revisions
    resolved_id, branch_label = self._resolve_revision_number(id_)
                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 767, in _resolve_revision_number
    self._revision_map
  File "/usr/local/lib/python3.11/site-packages/sqlalchemy/util/langhelpers.py", line 1140, in __get__
    obj.__dict__[self.__name__] = result = self.fget(obj)
                                           ^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/alembic/script/revision.py", line 246, in _revision_map
    down_revision = map_[downrev]
                    ~~~~^^^^^^^^^
KeyError: 'a4735d35d75'
```